1. Field of the Invention
The present invention provides an apparatus and method for replacing the tie plates of a railway.
2. Description of the Related Art
The rails of a railroad track are usually secured to cross ties by spikes driven into tie plates, with the tie plates located between the rail and the tie, and the head of the spike overlapping the bottom of the rail. The tie plates block lateral movement of the rails, and anchors are attached to the rail on either side of the tie are used to secure the rail against longitudinal movement.
Railroad ties occasionally must be replaced due to wear. After a tie is replaced, tie plates must be provided between the rail and the tie so that the rail may be properly secured to the tie.
Several other references propose various systems for use in replacing tie plates. For example, U.S. Pat. No. 4,280,613, issued to J. K. Stewart on Jul. 28, 1981, describes a tie plate conveying and orienting system.
U.S. Pat. No. 4,770,103, issued to F. Allmer on Sep. 13, 1988, describes a rail clamp. The rail clamp includes a pair of line-up wheels for engaging the inside edges of the rails. A pair of pivoting clamping arms, with each clamping arm having a disk rotatably mounted to its end, engages the outside edge of each rail, just below the rail""s ball. Movement of the clamping arms is controlled by hydraulic cylinders. Additionally, a stabilizer cylinder connecting a bridge crossing the chassis to the rail lifting assembly may either permit the rail lifting assembly to float to correspond with the rails, or may be locked in position.
U.S. Pat. No. 4,733,614, issued to G. Mohr et al. on Mar. 29, 1988, describes a machine for repairing a railway track. The machine includes a main chassis having various devices for repairing a railway, mounted on a chain drive under a railway vehicle. A counter weight mounted to the chain drive, moving the opposite direction, counters the effects of inertia.
U.S. Pat. No. 4,942,822, issued to D. J. Cotic on Jul. 24, 1990, describes an apparatus and method for automatically setting rail tie plates. The apparatus includes a frame having a ramp thereon. The ramp stores the tie plates, and includes a control mechanism for releasing them one at a time into a plate pocket. A reciprocated pusher then moves the plate from the plate pocket to its position on the tie.
U.S. Pat. No. 5,067,412, issued to J. Theurer et al. on Nov. 26, 1991, describes a tie plate-inserting machine. The front of the machine includes a crane broom with a tie plate-collecting magnet. A funnel adjacent to the crane leads to a conveyer, which terminates above a sorting table. A roller conveyer conveys ties from the sorter to a magazine. The magazine moves between a level position for receiving tie plates from the sorting table, and a lower position for dispensing the tie. The machine includes a tie plate-inserting arm slidably supported by a guide rod, for pushing the-tie plates from the magazine to their position below the rail. A lifting roller pivots between a raised position and a lowered position for permitting tie plates to be pushed thereon from the magazine to their final position below the rail.
U.S. Pat. No. 5,193,461, issued to J. Theurer et al. on Mar. 16, 1993, describes a tie exchange mean for both removing ties and inserting new ties. The tie exchange machine may move longitudinally along a guide track. A scarifier and track-lifting device are included. A mobile tie transporting crane may move towards or away from the tie exchange device, for transporting either new ties to be installed or old ties which have been removed. The tie-depositing device is a vertically adjustable forklift.
U.S. Pat. No. 5,305,692, issued to H. Madison et al. on Apr. 26, 1994, and assigned to Harsco Corporation, the assignee of the present invention, describes a tie exchanger mounted on a truck. The tie exchanger has a rail clamp table having rail clamps and a boom. The boom includes a tie clamp, and may pivot around the vertical axis to insert ties from either side of the tracks.
U.S. Pat. No. 5,331,899, issued to J. D. Holley on Jul. 26, 1994, describes a tie plate installer and remover using a magnetic wheel to insert or remove a tie plate. The tie plate installer includes a tie magazine from which tie plates are dropped into a shoot leading to the magnetic wheel, which then carries the tie plate to a position on the tie adjacent to its final location under the rail, and finally pushes it under the rail.
U.S. Pat. No. 5,419,259, issued to J. Theurer et al. on May 30, 1995, describes a ballast stabilizer. The ballast stabilizer has a rail clamp including a roller for engaging the rail""s ball, mounted on an arm secured at its other end to a lever. The opposite arm of the lever is secured to a hydraulic cylinder, so that extending the cylinder pushes inward on the clamp arm. A pair of vertical inner wheels are pushed against the gauge side of the rail""s ball by hydraulic cylinders. A shaking apparatus vibrates the machine parallel to the ties.
U.S. Pat. No. 5,722,325, issued to K. E. Glomski et al. on Mar. 3, 1998, describes a tie replacement apparatus including drip elements for holding a tie plate in place while the tie underneath is replaced.
U.S. Pat. No. 5,839,377, issued to D. M. Brenny et al. on Nov. 24, 1998, describes a machine for installing and removing elastic rail clips of the type used for fastening rails to concrete or wooden ties.
U.S. Pat. No. 6,170,401, issued to R. Miller et al. on Jan. 9, 2001, describes a rail vehicle for collection and distribution of railroad cross ties.
When replacing tie plates, it is useful to position the human operator where he may observe the operation, and make corrections as necessary. Additionally, it would be helpful for an operator in this position to be able to control movement of the vehicle to which the tie plate replacement apparatus is secured, thereby permitting rapid progression from one tie plate to the next. Furthermore, it is desirable to have the ability to utilize the tie replacement apparatus from different locations on the vehicle, depending on the nature of the obstacles surrounding the vehicle, for example, platforms, bridges, etc. Accordingly, a railway tie replacement apparatus and method incorporating these features is desired.
The present invention provides a railway tie insertion vehicle. The vehicle includes an operator""s chair on either side of the vehicle, with a main rail clamp and tie plate magazine located in close proximity to the operator""s chair. A secondary rail clamp is located at the rear of the vehicle. Each operator is provided with a tie plate insertion wand that may be utilized from either the side or the rear of the vehicle, and which includes controls for the vehicle.
The main rail clamps are located between the wheels of the vehicle. The rollers are placed underneath the rails"" ball where they roll along the rail until lifting is desired. When raising a rail is desired, lifting the clamp will cause the scissor arms to be drawn together, thereby gripping the rail and lifting it a sufficient distance to permit removal and insertion of the tie plate. Hydraulic cylinders are provided for moving the scissor arms away from the ball when unclamping the rail is desired. Additionally, a stabilizer cylinder connecting the wheel and frame assembly to the rail lifting assembly locks the rail in place laterally as the rail is raised, preventing buckling of the rail. The stabilizer cylinder also permits the operator to move the rail laterally in either direction to correct misalignment of the rail.
A secondary rail clamp, utilizing the same scissors mechanism but without the rollers, is located at the rear of the machine, permitting tie plates to be inserted from inside the tracks when the machine is used next to a platform or on a bridge, where access to the rail from the outside is restricted.
An operator""s chair is provided on either side of the vehicle, with each operator also having a tie plate insertion wand with a set of vehicle controls. Each operator has the ability to propel the vehicle, apply the brakes, control the rail clamps, adjust the rail lift on their individual sides, activate the emergency stop and shut-down mechanism, and blow the vehicle""s horn. The wand extends from the control box to a position adjacent the rail, wherein it may be used to manually push a tie plate under the rail. The control box attached to the wand is connected to the vehicle or electrical system through quick disconnect electrical connectors permitting it to be moved to the vehicle""s rear for use with the secondary clamps.
In general, tie plate will be deposited along the rail in advance of the tie plate replacement operation, so that the operators will not normally need to utilize a tie plate transported on the vehicle. However, in the event that a tie plate is not deposited in the location where it is needed, the vehicle does include a tie plate magazine, holding the tie plates vertically stacked. When a new tie plate is needed, the operator can activate a hydraulic pusher, which pushes the bottom tie plate from the magazine onto a ramp, so that the tie plate will slide down off the vehicle, landing adjacent to the rail.
The operator will control the vehicle from its cab when travelling to and from a work location. During a tie replacement operation the movement of the vehicle can be controlled by the operators on either side of the vehicle. The vehicle will travel along the track, stopping at each location wherein the tie plate must be replaced. The operators will use the scissors clamp to raise the rail, with the stabilizer cylinder plus the rail clamp""s location between the wheels of the vehicle preventing buckling of the rail while it is being lifted. The operator will use their wand to manually push the old tie plate out from under the rail. If a new tie plate has been deposited along the rail, the operator will simply use the wand to manually push the new tie plate into place. If not, then the operator will actuate the pusher for the tie magazine, driving a tie from the bottom of the magazine onto the ramp, where it will fall into position adjacent to the rail. The operator may then manually push the new tie into place, just as he would if it had been previously deposited. The operators will then,lower the rail, and move to the next tie replacement location.